You are given a map of a labyrinth, and your task is to find a path from start to end. You can walk left, right, up and down.
The first input line has two integers $n$ and $m$ : the height and width of the map.
Then there are $n$ lines of $m$ characters describing the labyrinth. Each character is . (floor), # (wall), A (start), or B (end). There is exactly one A and one B in the input.
First print "YES", if there is a path, and "NO" otherwise.
If there is a path, print the length of the shortest such path and its description as a string consisting of characters L (left), R (right), U (up), and D (down). You can print any valid solution.
5 8 ######## #.A#...# #.##.#B# #......# ########
· \n \n \n \n \n \n
YES 9 LDDRRRRRU
\n \n \n